Bonder chuck and optical component mounting structure interface

ABSTRACT

An optical component is adapted for pick-and-place-style installation on an optical submount or bench and compatible with a chuck of a bonder that picks-up the optical component, places it on the optical bench, and then typically solder bonds the optical component to the bench. In the current implementation, this optical component comprises an optical element, such as an optical fiber, lens, or MOEMS device, that is attached to a plastically deformable mounting structure. The optical component has a bench-attach surface that is used to bond the optical component to an optical bench. Further, the optical component has a bonder chuck engagement surface to which a bonder chuck attaches to manipulate the optical component, such as install it, on the optical bench.

RELATED APPLICATIONS

This application is a Continuation-in-Part of U.S. application Ser. No.09/648,349, filed on Aug. 25, 2000, and claims the benefit of the filingdate of Provisional Application No. 60/186,925, filed Mar. 3, 2000, theentire teachings of both applications being incorporated herein by thisreference.

BACKGROUND OF THE INVENTION

The production of integrated, hybrid micro-optical systems requires theprecision installation of optical elements, such as lenses, fibers andmicro-optical electro-mechanical systems (MOEMS) devices, on a submountor optical bench. In such systems, the beam diameters are typically lessthan one millimeter. As a result, these optical elements must typicallybe placed on the bench with accuracies of better than 20 micrometers(μm). Preferably, however, attachment accuracy of better than 10 μm ispreferred, with some applications requiring installation to an accuracyof better than 2 μm.

Further, the production of mechanically robust systems typicallyrequires solder attachment processes within the hermetic package. Thisprotocol avoids some of the long-term instabilities associated withepoxy bonding along with problems linked to carbon deposition on activedevice facets such as lasers.

One approach to manufacturing these integrated micro-optical systemsutilizes a combination of optical element mounting structures andpick-and-place style bonders. Specifically, flip-chip bonders have beenused in such systems. Further, the mounting structures may be designedto be susceptible to plastic deformation to enable active and/or passivealignment of the associated optical elements after the installation ofthe mounting structures on the bench.

SUMMARY OF THE INVENTION

The present invention is directed to optical component that is adaptedfor pick-and-place-style installation on an optical submount or bench.The invention is also directed to the co-design of the optical componentand the chuck, which picks-up the optical component, places it on theoptical bench, and then typically solder bonds the optical component tothe bench.

In general, according to one aspect, the invention features an opticalcomponent. This optical component comprises an optical element, such asan optical fiber, lens, or MOEMS device. The optical component has abench-attach surface that is used to bond the optical component to anoptical bench. Further, the optical component has a bonder chuckengagement surface to which a bonder chuck attaches to manipulate theoptical component, such as install it on the optical bench.

In the preferred embodiment, the optical component comprises a mountingstructure, which in some cases is plastically deformable to enable thealignment of an optical element to the surrounding optical system afterattachment to the optical bench.

Further, in the typical implementation, two bonder chuck engagementsurfaces are provided, one either lateral side of the optical element.

Preferably, the bonder chuck engagement surface is on a top surface of afoot portion of the mounting structure, with the bench-attach surfacebeing on a bottom surface of that foot.

In one implementation, armatures extend between a base of the opticalcomponent and an optical element interface, to which the optical elementis installed on the mounting structure.

In general, according to another aspect, the invention also features anoptical component manipulation system. This system comprises an opticalcomponent that has an optical element, a bench attach surface, and abonder chuck engagement surface. A bonder then comprises a vacuum chuckthat engages the optical component at the bonder chuck engagementsurface to then place the optical component on the optical bench.

Finally, according to still another aspect, the invention can becharacterized as an optical component installation process. The processcomprises picking an optical component with a vacuum chuck of a bonderat an engagement surface and then placing that optical component intoengagement with an optical bench. A chuck heater is then activated toinitiate bonding between the optical component and the optical bench.

The above and other features of the invention including various noveldetails of construction and combinations of parts, and other advantages,will now be more particularly described with reference to theaccompanying drawings and pointed out in the claims. It will beunderstood that the particular method and device embodying the inventionare shown by way of illustration and not as a limitation of theinvention. The principles and features of this invention may be employedin various and numerous embodiments without departing from the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, reference characters refer to the sameparts throughout the different views. The drawings are not necessarilyto scale; emphasis has instead been placed upon illustrating theprinciples of the invention. Of the drawings:

FIG. 1 is a perspective view of a bonder chuck holding an opticalcomponent according to the present invention;

FIG. 2 is a plan, elevation view of the inventive bonder chuck andoptical component with the chuck vacuum ports shown in phantom;

FIG. 3 is a plan elevation view of the bonder chuck holding a MOEMSoptical component according to the invention;

FIG. 4 is a perspective view of the MOEMS mounting structure held by thebonding chuck; and

FIG. 5 illustrates another example of a mounting structure having wingportions to facilitate manipulation by the bonder chuck.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows an optical component 100 being manipulated by a bonder 200,illustrating the codesign of the optical component 100 and the bonderchuck 202 according to the principles of the present invention.

The optical component 100 comprises a mounting structure 102 and anoptical element, which in this illustrated example is an optical fiber104.

The mounting structure comprises a base 110, an optical elementinterface 112, and left and right armatures 114A, 114B, which eitherdirectly connect, or indirectly connect, the base 110 to the elementinterface 112.

The base 110 comprises a laterally-extending base surface. In theillustrated example, the base surface extends in a plane of the x and zcoordinate axes, generally.

The base/base surface comprise alignment features 116. In someembodiments, these features are adapted to mate with opposite-genderedalignment features of an optical bench 10. In the specific illustratedimplementation, the alignment features are used by machine visionsystems to match to alignment marks or features 11 of the bench 10.

In the illustrated implementation, each of the armatures 114A, 114Bcomprises two segments. The vertically-extending segments 122, i.e.,extending at least partially in the y-axis direction, have two flexuresalong their length, in the illustrated embodiment. These flexures areregions of reduced cross-sectional area in the segments, which regionsextend in the direction of the z-axis. The vertically-extending segments122 facilitate the positioning of the optical element 104 along thex-axis. A purpose of the flexures is to isolate regions ofmicrostructural change, such as occurring in plastic deformation, inorder to make the yield forces, for example, readily predictable. Also,the flexures localize deformation on the armatures and consequentlydecrease the amount of force/movement required in the optical componentbefore plastic deformation is initiated in the armature.

Horizontally-extending (i.e., extending in the direction of the x-axis)segments 124 extend at least partially in the x-axis direction. In theillustrated embodiment, two flexures are found on each segment.

The horizontally-extending segments 124 allow the positioning of anoptical element, generally vertically along the y-axis. Armaturedeformation is facilitated by respective flexures.

In one implementation, the optical element 104 is bonded to the opticalelement interface 112, and specifically a bonding surface. This bondingis accomplished either through polymeric adhesive bonding or preferablysolder bonding. In other implementations, thermocompression bonding,thermosonic bonding, laser welding, reactive bonding, microwave bonding,or other bonding method is used.

The optical element interface, in some other implementations, comprisesa port for enabling an optical signal to pass transversely through thestructure. This enables optical access to the optical element componentby facilitating the propagation of an optical signal to and/or away fromthe element.

The mounting structure 102 further comprises a right foot 150A and aleft foot 150B. The bottom of each of these feet provides bench-attachsurfaces 152. In the preferred embodiment, these bench-attach surfaces152 are solder bonded to the bench 10. In some implementations, thesurfaces 152 are coated with predeposited solder or solder material suchas gold. In other implementations, only the bench is coated withpredeposited solder. Preforms used in still other embodiments.

In the illustrated embodiment, the top surfaces of the feet function asthe bonder chuck engagement surfaces 154. More specifically, the bonder200 comprises the bonder chuck 202. The bonder chuck 202 includes apick-up tool 206 that comprises a left prong 204 and a right prong 206.The tips of these prongs are aligned over the engagement surfaces 154.Typically, they pick-up the mounting structure 102 of the opticalcomponent by a vacuum chuck system, although, magnetic engagement can beused in other embodiments.

FIG. 2 better illustrates the vacuum system of the bonder chuck 202.Specifically, right and left vacuum ports 210, 212 are provided throughthe left and right prongs 204, 206 of the chuck 202. A vacuum is appliedin reservoir 208 and then transferred via these vacuum ports 210, 212 tohold the mounting structure 102 in engagement with the chuck 202.

FIG. 3 illustrates another embodiment of the chuck 202 and its co-designwith the mounting structure 102. Typically, the mounting structure 102of this optical component 100 holds a MOEMS-type optical element 104.Specifically, in the illustrated example, a Fabry-Perot tunable filteror optical, e.g., HR coated, optical membrane is the optical element104. In this example, the feet 150A, 150B of the mounting structure 102have top surfaces that function as the bond chuck engagement surfaces154, the bottom surfaces of the feet 150 function as the bench attachsurfaces 152.

FIG. 4 better shows the bench attach surfaces 152 of the mountingstructure 102. In some implementations, these bench attach surface areeither gold plated or are have predeposited solder 12 to facilitate thesolder bonding process.

FIG. 5 shows still another embodiment of the mounting structure 102.This mounting structure has two bench attach surfaces 152. The bonderchuck engagement surfaces 154, however, are provided on wing portionsextending from the armatures 114A, 114B.

Further, in this illustrated embodiment, the optical element 104 is alens, shown in phantom, that is bonded to interface 112 of the mountingstructure 102.

Generally, the embodiment of the mounting structure in FIG. 5 is viewedas less desirable. While easing somewhat the design tolerances of thebonder chuck, when the mounting structure 102 is installed on the bench,there is a risk of deformation to the right and left armatures 114A,114B if the bonder 200 applies excessive force when placing thecomponent onto the bench 10. Further, when a chuck heater 220 (seeFIG. 1) is activated, the prongs 204 indirectly heat the solder 12between the bench 10 and the bench-attach surfaces 152. In thisembodiment, that heat must travel over a longer distance, and not simplyacross the foot portion as in the embodiments of FIG. 1 and FIG. 4, forexample.

With reference to FIGS. 1 and 2, in operation, the bonder 200, andspecifically the chuck 202, is placed into engagement with the bonderchuck engagement surfaces 154 and the vacuum applied to ports 210, 212.The optical component 100 is then manipulated and/or placed intoengagement with the optical bench 10. A chuck heater 220 is thenactivated to heat the mounting structure 202 and specifically melt thesolder 12, see FIG. 4, between the bench attach surfaces 152 and thebench 10 to thereby solder bond, in the preferred embodiment, theoptical component to the bench 10, see FIG. 5.

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

What is claimed is:
 1. An optical component comprising: an opticalelement; a bench-attach surface that is used to connect the opticalcomponent to an optical bench; and a bonder chuck engagement surface towhich a bonder chuck attaches to manipulate the optical component.
 2. Anoptical component as claimed in claim 1, wherein the optical componentfurther comprises a mounting structure, the optical element beingattached to the mounting structure.
 3. An optical component as claimedin claim 2, wherein the optical component is plastically deformable toenable alignment of the optical element after attachment to the opticalbench.
 4. An optical component as claimed in claim 2, wherein themounting structure further comprises optical element interface on whichthe optical element in attached.
 5. An optical component as claimed inclaim 1, further comprising two bonder chuck engagement surfaces oneither lateral side of the optical element.
 6. An optical component asclaimed in claim 1, wherein the bonder chuck engagement surface is on atop surface of a foot portion, which has the bench-attach surface on abottom surface.
 7. An optical component as claimed in claim 1, whereinthe optical component further comprises a mounting structure thatcomprises a base, an optical element interface, and at least onearmature, extending between the base and the interface, and the bonderchuck engagement surface being on wing portion of the armature.
 8. Anoptical component manipulation system, comprising: an optical componentcomprising: an optical element, a bench-attach surface that is used toconnect the optical component to an optical bench, and a bonder chuckengagement surface to which a bonder chuck attaches to manipulate theoptical component; and a bonder comprising a vacuum chuck that engagesthe optical component at the bonder chuck engagement surface to placethe optical component on the optical bench.
 9. An optical componentmanipulation system as claimed in claim 8, wherein the bonder furthercomprises a chuck heating system to facilitate solder bonding of theoptical component to the optical bench.
 10. An optical componentmanipulation system as claimed in claim 8, wherein the optical componentfurther comprises a mounting structure.
 11. An optical componentmanipulation system as claimed in claim 10, wherein the mountingstructure is plastically deformable to enable alignment of the opticalelement after attachment to the optical bench.
 12. An optical componentmanipulation system as claimed in claim 10, wherein the mountingstructure further comprises optical element interface on which theoptical element is attached.
 13. An optical component manipulationsystem claimed in claim 8, further comprising two bonder chuckengagement surfaces on either lateral side of the optical element. 14.An optical component manipulation system as claimed in claim 8, whereinthe bonder chuck engagement surface is on a top surface of a footportion, which has the bench-attach surface on a bottom surface.
 15. Anoptical component installation process, comprising: picking an opticalcomponent with a vacuum chuck of a bonder at an engagement surface;placing the optical component into engagement with an optical bench; andactivating a chuck heater to initiate a bonding operation between theoptical component and the optical bench.
 16. An optical componentmanipulation system as claimed in claim 8, wherein the optical componentfurther comprises a mounting structure that comprises a base, an opticalelement interface, and at least one armature, extending between the baseand the interface, and the bonder chuck engagement surface is on wingportion of the armature.